What is the whole number ratio of the coefficients of ammonia to oxygen when the following equation is balanced correctly?

___${\text{N}}{{\text{H}}_3}{\text{(g)}} +$___${{\text{O}}_2}{\text{(g)}} \to$ ___${\text{NO(g)}} +$___${{\text{H}}_2}{\text{O(l)}}$

A.     1 : 2

B.     2 : 1

C.     4 : 5

D.     5 : 4

C